Burn wound dressing material

Abstract

The invention disclosed is a burn wound-adherent dressing material comprising a complex of gelatin and a water-soluble resin material such as polyethylenimine. The dressing material may be in the form of a preformed film or in the form of an aqueous coating which sets to a gel and dries to a continuous wound-adherent film in situ.

The embodiments of the invention in which an exclusive property or privilege is claimed is defined as follows: 
     
       1. A burn wound-adherent dressing material in the form of a continuous, wound-adherent, preformed film comprising a complex of gelatin of a Bloom # of 80 to 350 and a water-soluble polyethylenimine of molecular weight of 10,000 to 100,000, in a weight ratio of gelatin to polyethylenimine of 9:1 to 3:7. 
     
     
       2. A burn wound dressing according to claim 1, wherein the weight ratio of gelatin to polyethylenimine is about 1:1. 
     
     
       3. A burn wound dressing according to claim 2, wherein the gelatin has a Bloom # of about 150 and the polyethylenimine has a molecular weight of 40,000 to 60,000. 
     
     
       4. A burn wound dressing according to claim 3, wherein the thickness of the continuous film is 0.05 to 0.35 mm. 
     
     
       5. A burn wound dressing according to claim 4, wherein the thickness of the continuous film is 0.15 to 0.20 mm. 
     
     
       6. A burn wound dressing according to claim 1, additionally comprising a compatible plasticizer. 
     
     
       7. A burn wound dressing according to claim 6, wherein the plasticizer is glycerol. 
     
     
       8. A burn wound dressing according to claim 7, wherein the weight ratio of gelatin to polyethylenimine is about 1:1. 
     
     
       9. A burn wound dressing according to claim 8, wherein the gelatin has a Bloom # of about 150 and the polyethylenimine has a molecular weight of 40,000 to 60,000. 
     
     
       10. A burn wound dressing according to claim 9, wherein the thickness of the film is about 0.13 mm. 
     
     
       11. A burn wound dressing according to claim 10, wherein the weight ratio of gelatin to polyethylenimine to glycerol is about 5:5:2. 
     
     
       12. A method for making a continuous burn wound-adherent preformed film dressing material, comprising the steps of: (a) dissolving gelatin of a Bloom # of 80 to 350 and an aqueous solution of polyethlenimine of molecular weight of 10,000 to 100,000 in distilled water and mixing to form a gelatin/polyethylenimine complex in a weight ratio of gelatin to polyethylenimine of 9:1 to 3:7;   (b) adjusting the pH of the resulting aqueous solution by adding a suitable acid to lower the pH of the solution to 7-9.5;   (c) pouring the solution onto a flat surface; and   (d) drying in air at room temperature to form a gelatin/polyethylenimine complex continuous, burn wound-adherent preformed film.   
     
     
       13. A method according to claim 12, wherein the suitable acid is hydrochloric acid. 
     
     
       14. A method according to claim 13, wherein the pH is adjusted to about pH 9. 
     
     
       15. A method according to claim 14, wherein the weight ratio of gelatin to PEI is about 1:1. 
     
     
       16. A method according to claim 15, wherein the gelatin has a Bloom # of about 150 and the polyethylenimine has a molecular weight of 40,000 to 60,000. 
     
     
       17. A method of preparing a burn-wound dressing material in the form of a substantially uniform, aqueous coating comprising a complex of gelatin of a Bloom # of 80 to 350 and a water-soluble polyethylenimine of molecular weight of 10,000 to 100,000, in a weight ratio of gelatin to polyethylenimine of 7:3 to 3:7 comprising the steps of (a) providing an aqueous solution of said gelatin;   (b) providing an aqueous solution of said polyethylenimine;   (c) mixing solutions from (a) and (b) to form said aqueous gelatin/polyethylenimine complex;   (d) applying the aqueous complex at a temperature of about 30° C. to a burn wound;   (e) spreading the aqueous complex substantially uniformly over the surface of the wound; and   (f) permitting the aqueous complex to set to a gel and dry to a continuous burn wound-adherent film in situ.   
     
     
       18. A method according to claim 17, wherein the gelatin and polyethylenimine components are maintained apart until use. 
     
     
       19. A method according to claim 18, wherein the aqueous gelatin/polyethylenimine complex comprises 36.5 to 40 parts of gelatin plus polyethylenimine per 100 parts of water. 
     
     
       20. A method according to claim 17, wherein the pH of the aqueous gelatin/polyethylenimine complex is 8-10.5. 
     
     
       21. A method according to claim 18, wherein the pH of the PEI solution is 8-11. 
     
     
       22. A method according to claim 21, wherein the weight ratio of gelatin to polyethylenimine is about 1:1. 
     
     
       23. A method according to claim 22, wherein the gelatin has a Bloom # of about 150 and the polyethylenimine has a molecular weight of about 50,000.